OFF: CD playing time (was HW: Live at The Kinetic Playground)

[Doug Pearson]

Ah, this is a good question, even if (more than?) a bit off-topic.  Since
I've had a bit of experience at this sort of thing, here are some pertinent
points:

It is possible to manufacture CD's that play for over 80 minutes (I own a
couple - the Mission of Burma collection on Rykodisc clocks in at 80:08,
and a live Swans one is 80:02 - and these were both manufactured in the
late 1980s), BUT I have been unable to find any CD manufacturers in the
United States that will make them (otherwise, there would be an additional
track on the 'Assassins of Silence' Hawkwind tribute CD :^( , but I
digress).  The "official" reason for this is that, yes indeed, as CD's get
over 78 minutes or so, they become more susceptible to defects.  I would
suspect that the cause is that there's a bit of "slop" inherent in cutting
a CD relative to where (how close to the center) the data begins.  With
long CD's, if the data starts too far away from the center, it may "spill
over" the edge of the CD, causing a loss of the last few minutes or seconds
of music.  I have experienced a few longer (> 70 minute) CDs that
"locked-up" and refused to play the last few minutes, so this may have been
the cause.   These seemed to occur intermittently within a single run (in
other words, I was able to send the disc back to the label and received a
playable replacement), and were not greatly affected by the quality of the
player (a high-quality one might play a tiny bit more than a cheap
portable, but not enough to really matter).  Never tried them in a CD-ROM
drive, though (I would suspect that this kind of defect would not be
improved much, but a 4x/8x/16x etc. CD-ROM drive may have better tracking
with a CD that skips or has other non-time-related defects).

On Mon, 6 Jul 1998 22:02:57 +0100, Chris Warburton
<desdinova at EARTHLING.NET> posted the following:
>At 11:03 06/07/98 -0400, you wrote:
>>(Actually, if the Kinetic Playground bootleg had not been a CD-R one, it
>>might have avoided the jarring cuts described in another posting,
>>because you can squeeze almost 80 minutes on a silver CD.  I have two
>>Bevis Frond CDs that clock in over 79 minutes, and I've heard "the
>>longest CD" is just a tad over 80 minutes.  I have some silver CD
>>bootlegs that cruise the 78 minute mark.  It's surprising what proper
>>mastering can do for you.:)

Proper mastering will make the music on a CD sound better, but
length-related problems are more a function of the manufacturing process;
most pressing plants probably just aren't accurate enough.

>I have quite a few that make it over the 78 minute mark, but none over the
>80.  I've also had a couple just lately that wouldn't play on my
>(expensive) CD-player, nor on my boom-box, but would play on my CD-ROM (not
>apparently time-related) - any comments anybody?